Process for pheresis procedure and disposable pheresis bowl therefor

Abstract

A pheresis process and apparatus for carrying it out. Blood from a donor is transferred to a pheresis bowl formed to have a red cell reservoir and a plasma reservoir in fluid communication through plasma ducts. The pheresis bowl is adapted for centrifuging to separate the red cells and plasma. This separation is accomplished simultaneously with the withdrawal of blood from the donor. At the end of the withdrawal the red cells are returned to the donor. The connection with the donor is thus continuously maintained during the entire procedure. The process is safe, fast and economical.

I claim: 
     
       1. A unitary plasmapheresis centrifuge rotor, comprising, in combination: a. a red cell reservoir in the shape of a centrifuge bowl, said reservoir having a bottom wall which defines a drainage angle of at least 5° and having a whole blood inlet and a plasma outlet;   b. a plasma reservoir in axial alignment with said red cell reservoir;   c. plasma duct means providing fluid communication between the plasma outlet of said red cell reservoir and said plasma reservoir;   d. air vent means communicating with said plasma reservoir; and,   e. means for engaging a centrifuge drive system whereby said centrifuge rotor can be spun to separate whole blood entering said red cell reservoir into a plasma component and a red cell component.   
     
     
       2. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said red cell reservoir is positioned below said plasma reservoir. 
     
     
       3. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said drainage angle in said red cell reservoir ranges between about 5° and about 30°. 
     
     
       4. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein sid red cell reservoir has internal baffle means. 
     
     
       5. A unitary plasmapheresis centrifuge rotor in accordance with claim 4 wherein said baffle means comprise a feed baffle section parallel with and spaced from said bottom wall of said red cell reservoir, a centrally positioned feed hood section and an axially aligned cylindrical core section, the chambers defined by said sections forming said baffle means being in fluid communication through fluid ports. 
     
     
       6. A unitary plasmapheresis centrifuge rotor in accordance with claim 5 wherein said red cell reservoir is formed to have a central cylindrical configuration. 
     
     
       7. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said red cell reservoir has an upper, centrally positioned reentrant air through which said plasma duct means are joined to said red cell reservoir. 
     
     
       8. A unitary plasmapheresis centrifuge rotor in accordance with claim 7 wherein said plasma duct means comprise oppositely disposed ducts, each of which includes radial duct sections extending outwardly and at an upwardly directed slope from said reentrant weir of said red cell reservoir. 
     
     
       9. A unitary plasmapheresis centrifuge rotor in accordance with claim 8 wherein said radial duct sections are of larger diameter than the remaining portion of the duct length. 
     
     
       10. A unitary plasmapheresis centrifuge rotor in accordance with claim 8 wherein said upwardly directed slope of said radial duct sections is such as to cause plasma, during the rotation of said bowl, to be centrifuged against the lower walls of said radial duct sections and to define an air passage within said radial duct sections above said plasma. 
     
     
       11. A unitary plasmaphersis centrifuge rotor in accordance with claim 1 wherein the cross sectional configuration of said plasma reservoir taken normal to the axis of rotation of said bowl is similar to a figure eight thereby to define two oppositely disposed chambers within said plasma reservoir. 
     
     
       12. A unitary plasmapheresis centrifuge rotor in accordance with claim 11 including fluid communication means between said chambers. 
     
     
       13. A unitary phasmapheresis centrifuge rotor in accordance with claim 1 including means within said plasma reservoir to divide said reservoir into two chambers in fluid communication. 
     
     
       14. A unitary plasmapheresis centrifuge rotor in accordance with claim 13 wherein said means to divide said plasma reservoir into two chambers comprises a baffle extending through said plasma reservoir in a plane intersecting the axis of said rotor. 
     
     
       15. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said duct means comprise oppositely disposed ducts. 
     
     
       16. A unitary plasmapheresis centrifuge rotor in accordance with claim 15 wherein said ducts are located on opposite sides of a center plane intersecting the axis of said rotor. 
     
     
       17. A unitary plasmapheresis centrifuge rotor in accordance with claim 15 wherein said plasma ducts communicate with the tops of said red cell and plasma reservoirs at a radius from the center of rotation of said bowl equal to about one-third the outside radius of said reservoirs. 
     
     
       18. A unitary plasmapheresis centrifuge rotor in accordance with claim 17 wherein said radius from the center of rotation is greater for said plasma reservoir than for said red cell reservoir. 
     
     
       19. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said vent means also communicates with said red cell reservoir. 
     
     
       20. A unitary plasmapheresis centrifuge rotor in accordance with claim 19 wherein said vent means comprises tubing means extending from the upper part of said red cell reservoir through said plasma reservoir and terminating with a connecting end outside said plasma reservoir, said tubing means defining first and second parallel fluid passages both of which extend to said connecting end, said first passage providing fluid communication with said red cell reservoir and the upper part of said plasma reservoir and said second fluid passage providing fluid communication with the lower part of said plasma reservoir. 
     
     
       21. A unitary plasmapheresis centrifuge rotor in accordance with claim 20 including vent filter means affixed to said tubing means. 
     
     
       22. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein said red cell reservoir has a volume sufficient to contain the mass of red cells derived form one unit of whole blood and said plasma reservoir has a volume sufficient to contain the plasma derived form at least two units of whole blood. 
     
     
       23. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 wherein the cross sectional configurations of said red cell and plasma reservoirs taken normal to the axis of rotation of said bowl are circular. 
     
     
       24. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 further characterized as being formed from a blood-compatible synthetic resin material. 
     
     
       25. A unitary plasmapheresis centrifuge rotor in accordance with claim 24 wherein said bowl is formed as two half-sections which are then sealed to define said red cell and plasma reservoirs and said duct means. 
     
     
       26. A unitary plasmapheresis centrifuge rotor in accordance with claim 25 wherein said bowl is blow molded. 
     
     
       27. A unitary plasmapheresis centrifuge rotor in accordance with claim 1 including form-fitting shoe means to support said rotor during rotation and adapted for engagement with a centrifuge chuck. 
     
     
       28. A unitary plasmapheresis centrifuge rotor comprising, in combination: a. a lower red cell reservoir in the shape of a centrifuge bowl, said reservoir having a bottom wall which defines a drainage angle of at least 5° and has a central opening suitable for engagement with tubing defining a fluid channel, said red cell reservoir having an upper centrally positioned reentrant weir;   b. an upper plasma reservoir in axial alignment with said lower red cell reservoir said plasma reservoir having means to divide it into two chambers in fluid communication;   c. oppositely disposed ducts providing fluid communication between said red cell reservoir and said plasma reservoir, each of said ducts including radial duct sections extending outwardly and at an upwardly directed slope from said reentrant weir of said red cell reservoir; and   d. vent means providing fluid communication between the ambient atmosphere and said red cell and plasma reservoirs and between said reservoirs.   
     
     
       29. A blood pheresis system, comprising in combination a. a plasma pheresis bowl as defined in claim 1;   b. phlebotomy needle means adapted for connection with a donor of whole blood and including means to admix an anticoagulant with said whole blood;   c. connecting means providing fluid communication between said red cell reservoir and said phelbotomy needle means, said connecting means comprising a flexible connector, a rigid tubing, rotary seal means and flexible tubing; and   d. pumping means associated with said flexible tubing for pumping anticoagulated whole blood from said donor into said red cell reservoir and for returning red cells from said red cell reservoir to said donor.   
     
     
       30. A blood pheresis system in accordance with claim 29 including means to admix saline solution or volume extender with said red cells during their return to said donor. 
     
     
       31. A blood pheresis system in accordance with claim 29 including shoe means configured to fit around and support said rotor and to be engaged with a centrifuge chuck.